The present invention relates to a mechanical tool. More particularly, the present invention relates to a tool for assembling a trampoline.
Trampoline springs are usually installed and removed manually. The procedure entails considerable difficulty and sometimes damage to the equipment and/or injury to the hands.
U.S. Pat. (U.S.P.) No. 4,976,001 to Thornton et al. discloses a hand-held and hand-manipulated tool adapted to hook or unhook a helical spring such as a trampoline spring, to or from an anchoring structure such as the frame of a trampoline. The tool comprises an elongate level "of the second kind." The end of the lever is adapted to rest on the surface of the spring as a fulcrum. The opposite end of the lever provides the power arm of the lever, and has a handle formed at its free end transversely of the lever, and a work arm depending from between the power arm and the fulcrum adjacent to the fulcrum and formed to receive and hold the unanchored loop, hook, eye end of the spring, whose other end is anchored to a supporting structure such as the grommeted margin of the trampoline jump sheet.
When the tool engages the spring and is used as a lever, the force exerted by the user on the power arm longitudinally and usually also transversely, to move the anchoring loop, eye, or hook, or eye end of the spring, whose other end is anchored to a supporting structure such as the grommeted margin of the trampoline jump sheet.
When the tool engages the spring and is used as a lever, the force exerted by the user on the power arm results in an elastic distortion of the spring longitudinally and usually also transversely, to move the anchoring loop, eye, or hook to a position for hooking or unhooking to an anchoring structure such as the rigid support frame for the flexible jump sheet of a trampoline.
The power arm (20) has a transversely-oriented handle portion (20a) at the free end of an outwardly-curved portion (20b), for grasping by the user. At the opposite end of the tool is formed a forked fulcrum member (21). Between the power arm (20) and the fulcrum member (21), a work arm (22) projects angularly opposite to the outwardly-curved portion (20b). The work arm (22) is located adjacent to the fulcrum member (21) but remote from the handle portion (20a) of the power arm (20), and is formed as a re-entrantly hooked member (22a) for engaging a portion of the circumference of an anchoring loop (11b) in its overhung bed (22b).
The loop (11b) of a spring (11) is engaged by the re-entrantly formed hook (22a) of the work arm (22) so as to be lifted when the power arm (20) is moved upwardly around a center established by the free end of the fulcrum member (21) resting on the spring (11), thereby distorting the spring (11) both longitudinally and transversely. The re-entrantly formed hook (22a) is constructed and arranged so that a portion of the loop (11b) of the spring (11) is engaged in a recess (22b) closed on three sides by portions of the work arm (22) and open only at the top, and so that a portion (22c) of the work arm (22) forms an overhang or overhung bed (22b) above the loop (11b). Thus, in order to disengage the loop (11b) it is necessary to move the hook (22a) downwards, then sideways, with respect to the loop (11b).
If it is desirable to stretch the spring only longitudinally, this is accomplished by grasping the curved portion (20b) of the power arm (20) approximately in line with the longitudinal axis of the spring, thereby eliminating the application of a force tending to twist the spring (11) about the fulcrum point. The tool (10) is then pulled along the longitudinal axis of the spring (11) to stretch the spring longitudinally. Then the loop (11b) is moved transversely by moving the tool (10) as well as the spring (11) transversely, the opposite loop (11a) of the spring (11) pivoting about its anchorage in a grommet (17).
As the tool (10) is pulled to stretch the spring (11) longitudinally, the tool (10) is moved vertically upward to position the free end (23) of the open hook (11b) above a receiving hole (12) in a trampoline frame member (13). The tool (10) is then moved vertically downward to insert the hooked end (23) and the entire hooked loop (11b) of the spring (11) into the receiving hole (12). The pulling force on the tool (10) is then released and the tool removed. To remove the spring (11) from the anchoring frame (13), the reverse procedure is employed. For use of the tool (10) in this manner only, the tool could be constructed with a shortened power arm (20) so that the graspable portion of the arm (20) would be vertically oriented in a plane aligned with the longitudinal axis of the spring. Furthermore, the curved portion (20b) could be a straight continuation of the straight portion (20c) if no accommodation of an anchoring part is required.
U.S. Pat. No. 1,889,167 to Anderson discloses a spring-installation tool comprising an elongated member having one end adapted for insertion into the aperture of a spring abutment. The elongated member is provided on one face thereof with a longitudinal groove extending to the end of the tool. The other face of the member is provided, adjacent the end of the member, with a shoulder for engagement with the spring abutment into the aperture of which the end of the member is inserted.
U.S. Pat. No. 2,042,287 to Allievi et al. discloses a spring tool which comprises a bar (1) having a laterally and rearwardly offset portion at one end, a handle (2), and a claw (6) at the extremity of the offset portion disposed at an approximate right angle to the longitudinal axis of the bar. The claw is wider than the bar, and has a concave face conforming to the general curvature of a pin or post. The bar has a spur (7) on its rear face adjacent to the offset curved portion and disposed between the handle (2) and the claw (6). The spur (7) serves as a stop to limit the movement of a spring hook on the bar. The other end of the bar (1) tapers to a point which constitutes a sharp prong (3) utilized in removing or coupling the hooked end of a spring into a hole or opening.
The claw (6) end of the bar (1) is inserted through a hook (8) at one end of a spring (9), and the claw (6) is positioned against the far side or face of a pin or post (10). The bar (1) is then swung so as to expand the spring (9) and cause the hooked end (8) of the spring (9) to ride down and off the curved or offset portion (4) of the bar (1) and off the claw (6) on to the pin or post (10).
Alternatively, the prong (3) end of the bar (1) is inserted through the hook (8) of the spring (9), and then positioned through a hole or opening (11) as the tool is swung in a direction which causes the hooked end (8) of the spring (9) to ride down the tapered portion (3) of the bar (1) into the hole or opening (11).
U.S. Pat. No. 2,274,981 to Grubb discloses a tool for the insertion and removal of coil springs under heavy tension. The tool comprises a hollow tubular stem (1) having at one end thereof a handle in the form of a hollow tube (3) positioned transversely of the stem, and at its other end a circular flange (5).
To remove a spring from its position, e.g., in the brake assembly of an automotive vehicle, the end of the extension rod is inserted into the opening through which the hooked end of the spring extends, and the flange is worked under the end of the spring until the hooked portion enters a radial notch in the flange. When the hooked end has been grasped by the tool, a partial rotation of the tool in a direction which produces additional tensioning of the spring will suffice to draw the hooked portion of the spring from the opening, thereby freeing it from the brake assembly.
U.S. Pat. No. 2,673,392 to McFadden discloses a tool for removing and replacing springs in and from structures. The tool comprises a thrust member support (1) provided as its lower end with notches (2) for engagement with the rail of a bed spring. The member (1) comprises two portions (1a and 1b) spaced apart and secured by a spacer member (3). A lever member (4), which at one end is shaped to provide a handle (4a), is pivotally mounted on the support member (1), and extends between the side members (1a, 1b). The lever member (4) is mounted on a pivot pin (5). At one end the lever member (4) is provided with an angular portion (4b) which is pivotally connected (at 4c) to an arcuate ratchet member (6).
The arcuate member (6) is provided with a set of teeth (8) adapted for cooperation with the end of the support member (1) by providing the end of the support member (1) with a beveled corner portion (9) or plate (10) between the parallel side members (1a, 1b). The end of the ratchet member (6) is provided with a pair of hooks (13, 13a).
To replace a spring, the thrust member support (1) engages the rail of a bed spring, with the spaced members (1a and 1b) straddling the spring. One of the hooks (13 or 13a) engages the last hook coil of the spring, and the lever (4) is depressed, expanding the spring. Concurrently, the end of the support (1) engages the ratchet teeth (8) of the arcuate member (6), which is lifted upward with respect to the support (1). When the spring has been stretched sufficiently so that the portion of the spring which is in engagement with a hole at the end of a strip (16) may be removed, the end of the support member (1) will be in engagement with a tooth (8) of the ratchet member (6), and the spring will be held in extended condition, thereby enabling the operator to remove the end of the spring from Its engagement with the Strip (16).
To insert a spring, one end of the spring is attached through a hole in the rail of the bed spring, the thrust member (1) is placed in engagement with the rail so that it straddles the spring, a hook (13, 13a) engages the looped end of the spring, and by manipulation of the handle (4) the spring is stretched sufficiently to enable the looped end of the spring to engage a hole in the strip (16). As the handle (4) is operated, the ratchet member (6) is raised and the end of the support member (1) caused to engage a tooth (8) which will hold the lever (4) in the adjusted position necessary to permit the attachment of the spring to the strip (16).
U.S. Pat. No. 2,811,772 to Johnson discloses a hand tool for removing the hooked end of a spring from a restraining stud and for applying the hooked end of a spring thereto.
The tool comprises a shank having a laterally-disposed portion, with an enlarged body axially fixed to one end of the shank. The enlarged body has a reduced portion at its free end, an axial bore for receiving a spring-retaining stud, and a projecting arcuate lip on the free end of the enlarged boy. The inner surface of the lip is a continuation of the axial bore, and the outer surface of the lip projects outwardly of the adjacent surface of the reduced portion of the enlarged boy, to provide a shoulder and a spiral groove in the lip tapering to a thin leading edge and extending diagonally from one end of the lip through the lip and the shoulder and into the reduced portion of the enlarged body.
A spring-retaining stud is disposed between the ends of a spring-attaching hook disposed on the stud. Upon rotation of the enlarged body, the hook engages the spiral groove and moves the hook rearwardly into engagement with the reduced portion of the enlarged body, to facilitate removal of the hook from the stud.
U.S. Pat. No. 4,068,363 to Costa discloses a hand tool for the manipulation of coil springs. The tool includes a handle and a shank secured thereto at one end thereof. The other, free end of the shank is integrally provided with a coil spring hook-type engaging portion disposed perpendicularly to the shank. The dimensions of the shank and hook portions permit the tool to be inserted and disposed within the central portions of a coil spring and there used to manipulate the spring.
U.S. Pat. No. 4,870,737 to Navarro discloses a brake-spring removal tool. The tool includes laterally-extending spurs which engage the coiled portion of the spring, thereby allowing the user to remove or install the spring.
The tool (10) has an elongated handle (33). The handle (33) has a tapered portion (32) leading into an angled portion (31). The angled portion (31) of the handle (33) terminates in a block (21). Each side of the block (21) has an upper spur (22) and a lower spur (23) projecting perpendicularly from the side of the block (21).
The user inserts one of the spurs (22 or 23) into the coiled portion of a brake spring. When the user twists the tool (10) slightly, the spurs will engage the inside of the coiled portion of the spring and extend the spring, thereby reducing the inside diameter of the spring. The user then lifts the spring upwards and thereby removes the spring from its mounting post.
U.S. Pat. No. 5,165,154 to Miller discloses a hand-operated tool which is used to attach and remove the springs anchored to and extending between a pair of brake shoes. The tool includes two separate elements which cooperatively operate as a unit to manipulate the springs into proper engagement with the brake shoes. The first element is a rigid plate, and the second element is a lever.
The plate can be slidingly positioned between the shoes adjacent the spring after a first, hooked end of the spring has been anchored to an aperture in the top shoe. The plate includes a boss projecting from either side thereof, which serves as a fulcrum for the lever.
The lever includes a handle with a linear shank extending therefrom, terminating in a free, distal end. The distal end has a rounded tip, and includes at least one annular groove adjacent thereto which is used to grasp the second, hooked end of the spring. With the lever positioned against the boss on the plate, the lever can be used to pull the second end of the spring into engagement with an aperture in the bottom of the shoe.